复合添加剂在交直流叠加电解精炼铜中的电化学行为研究

The study of electrochemical behaviors of composite additive in the copper electrorefining by AC/DC

自制一系列新型复合添加剂,通过大量实验遴选出一种效果较好的复合添加剂,采用三电极体系的动电位法测定了在该添加剂作用下阴极铜沉积循环伏安曲线和交流阻抗曲线图,结合金相显微镜照片,研究其在交直流叠加电解精炼铜中的作用并对其作用机理进行简单的阐述。结果表明:自制复合添加剂具有增极化作用,可以显著改善阴极铜表面质量,但不改变阴极铜沉积反应机理;添加剂存在时,交直流叠加电解在保证阴极铜质量前提下,可以将电流密度提高到360 A/m^2左右;电解时间较长时,交直流叠加电解仍然可以一定程度上改善阴极铜质量。

A series of new composite additives were made, and a better-performing composite additive was selected by a large number of experiments. To study the mechanism of the self-made additive in the electro-refining of copper, the cyclic voltammetry curves and impedance spectroscopy were determined with a three-electrode system. Combination of metaloscope pictures, the mechanism of additives was discussed. The results indicated that the self-made additive had an action of increasing polarization and can improve the quantity of cathode copper, but did not change the reaction mechanism of copper deposition. When the additive exists, the current density can reach about 360 A/m2 in the case of ensuring the quantity of cathode copper. With the time of electrolysis prolonging, the quality of cathode copper can be still improved to some extent.